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D. W. van Krevelen

Bio: D. W. van Krevelen is an academic researcher from AkzoNobel. The author has contributed to research in topics: Mass transfer & Adipic acid. The author has an hindex of 16, co-authored 43 publications receiving 3999 citations.

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Journal ArticleDOI
TL;DR: In this paper, it was shown that the partial pressures of the reacting substances appeared to influence the reaction rate, and a formula depicting this influence was derived, which may be interpreted by assuming two successive reactions, namely the reaction between the aromatic and the oxygen on the surface, and the re-oxidation of the partly reduced surface by means of oxygen.

1,613 citations

Journal ArticleDOI
D. W. van Krevelen1
01 Aug 1975-Polymer
TL;DR: In this paper, it was shown that the amount of char and the incombustible gases that may be formed in thermal decomposition are very important quantitative measures of flame resistance.

855 citations

Journal ArticleDOI
TL;DR: In this paper, the spherulite growth rate, the maximum spherule radius, and the overall rate of crystallization of poly(ethylene terephthalate) (PETP) were measured by means of scattering and transmission of depolarized light.
Abstract: The spherulite growth rate, the maximum spherulite radius, and the overall rate of crystallization of poly(ethylene terephthalate) (PETP) were measured by means of scattering and transmission of depolarized light. The influence of crystallization temperature, molecular weight, and additives on the above-mentioned quantities was investigated. An expression has been derived for the spherulite growth rate of PETP as a function of crystallization temperature and the number-average molecular weight for Mn in the range of 19,000 to 39,000.

118 citations


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Book
17 Sep 1999
TL;DR: In this paper, Hansen et al. presented a method for computing Hansen solubility parameters in a multicomponent mixture of solvents, using the FH model.
Abstract: Solubility Parameters - An Introduction C.M. Hansen Hildebrand Parameters and Basic Polymer Solution Thermodynamics Hansen Solubility Parameters Methods and Problems in the Determination of Partial Solubility Parameters Calculation of the Dispersion Solubility Parameter deltad Calculation of the Polar Solubility Parameter deltap Calculation of the Hydrogen Bonding Solubility Parameter deltah Supplementary Calculations And Procedures Hansen Solubility Parameters for Water Theory - The Prigogine Corresponding States Theory, the c12 Interaction Parameter, and the Hansen Solubility Parameters C.M. Hansen Hansen Solubility Parameters (HSP) Resemblance Between Predictions of Hansen Solubility Parameters and Corresponding States Theories The c12Parameter and Hansen Solubility Parameters Comparison of Calculated and Experimental c12 Parameters General Discussion Postscript Statistical Thermodynamic Calculations of the Hydrogen Bonding, Dipolar, and Dispersion Solubility Parameters C. Panayiotou Theory Applications Discussion and Conclusions Appendix I: The Acid Dimerization Appendix II: An Alternative Form of the Polar Term Appendix III: A Group-Contribution Method for the Prediction of delta and deltaD Hansen Solubility Parameters (HSP) in Thermodynamic Models for Polymer Solutions G.M. Kontogeorgis Group Contribution Methods for Estimating Properties of Polymers Activity Coefficients Models Using the HSP Conclusions and Future Challenges Appendix I: An Expression of the FH Model for Multicomponent Mixture Methods of Characterization - Polymers C.M. Hansen Calculation of Polymer HSP Solubility - Examples Swelling - Examples Melting Point Determinations - Effect of Temperature Environmental Stress Cracking Intrinsic Viscosity Measurements Other Measurement Techniques Methods of Characterization - Surfaces C.M. Hansen Hansen Solubility Parameter Correlations with Surface Tension (Surface Free Energy) Method to Evaluate the Cohesion Energy Parameters for Surfaces A Critical View of the Critical Surface Tensions A Critical View of the Wetting Tension Additional Hansen Solubility Parameter Surface Characterizations and Comparisons Self-Stratifying Coatings Maximizing Physical Adhesion Methods of Characterization for Pigments, Fillers, and Fibers C.M. Hansen Methods to Characterize Pigment, Filler, and Fiber Surfaces Discussion - Pigments, Fillers, and Fibers Hansen Solubility Parameter Correlation of Zeta Potential for Blanc Fixe Carbon Fiber Surface Characterization Controlled Adsorption (Self-Assembly) Applications - Coatings and Other Filled Polymer Systems C.M. Hansen Solvents Techniques for Data Treatment Solvents and Surface Phenomena in Coatings (Self-Assembly) Polymer Compatibility Hansen Solubility Parameter Principles Applied to Understanding Other Filled Polymer Systems Hansen Solubility Parameters of Asphalt, Bitumen and Crude Oils P. Redelius Models of Bitumen Asphaltenes Molecular Weight Polarity Solubility Parameters of Bitumen Testing of Bitumen Solubility Hildebrand Solubility Parameters Hansen Solubility Parameters (HSP) The Solubility Sphere Computer Program for Calculation and Plotting of the Hansen 3D Pseudosphere Components of Bitumen Bitumen and Polymers Crude Oil Turbidimetric Titrations BISOM Test Determination of Hansen Solubility Parameter Values for Carbon Dioxide L.L. Williams Methodology One-Component Hildebrand Parameter as a Function of Temperature and Pressure Three-Component (Hansen) Solubility Parameters - Pure CO2 Temperature and Pressure Effects on HSPs: deltad Temperature and Pressure Effects on HSPs: deltap Temperature and Pressure Effects on HSPs: deltah Addendum Appendix I: Ideal Solubility of Gases in Liquids and Published CO2 Solubility Data Use of Hansen Solubility Parameters to Identify Cleaning Applications for "Designer" Solvents J. Durkee A Variety of Solvents Pathology of Soils HSP of Multiple-Component Soils Method for Calculating HSP of Composites (Soils or Solvents) More Realistic View About Evaluating HSP of Composite Soils Method for Choice of Suitable Solvents Reference Soils for Comparison Identification of Designer Solvents An Open Question - Answered Limiting RA Value For Expected Good Cleaning Performance Application of HSP Methodology to Cleaning Operations Analysis of Capability of Designer Solvents Applications - Chemical Resistance C.M. Hansen Chemical Resistance - Acceptable-or-Not Data Effects of Solvent Molecular Size Chemical Resistance - Examples Special Effects with Water Applications - Barrier Polymers C.M. Hansen Concentration-Dependent Diffusion Solubility Parameter Correlations Based on Permeation Phenomena Solubility Parameter Correlation of Polymer Swelling Solubility Parameter Correlation of Permeation Coefficients for Gases General Considerations Applications - Environmental Stress Cracking in Polymers C.M. Hansen ESC Interpreted Using HSP ESC With Nonabsorbing Stress Cracking Initiators Hansen Solubility Parameters - Biological Materials C.M. Hansen and T. Svenstrup Poulsen Hydrophobic Bonding and Hydrophilic Bonding (Self-Association) DNA Cholesterol Lard Human Skin Proteins - Blood Serum and Zein Chlorophyll and Lignin Wood Chemicals and Polymers Urea Water Surface Mobility Chiral Rotation, Hydrogen Bonding, and Nanoengineering Absorption and Diffusion in Polymers C.M. Hansen Steady State Permeation The Diffusion Equation Surface Resistance Side Effects Film Formation by Solvent Evaporation Anomalous Diffusion (Case II, Super Case II) Applications - Safety and Environment C.M. Hansen Substitution Alternative Systems Solvent Formulation And Personal Protection For Least Risk The Danish Mal System - The Fan Selection of Chemical Protective Clothing Uptake of Contents by a Plastic Container Skin Penetration Transport Phenomena The Future Hansen Solubility Parameter Data and Data Quality Group Contribution Methods Polymers as Points - Solvents as Spheres Characterizing Surfaces Materials and Processes Suggested for Further Attention Theoretical Problems Awaiting Future Resolution Appendices Hansen Solubility Parameters for Selected Solvents with the major contribution of Hanno Priebe Hansen Solubility Parameters for Selected Correlations Solubility Data for the Original 33 Polymers and 88 Solvents Index * Each Chapter contains an Abstract, an Introduction, and a Conclusion. Many chapters may also include Acknowledgements, Additional Discussions or General Comments/Considerations, and chapter-specific Key Words, Abbreviations, and Symbols

2,532 citations

Journal ArticleDOI
Rolf Sander1
TL;DR: According to Henry's law, the equilibrium ratio between the abundances in the gas phase and in the aqueous phase is constant for a dilute solution as discussed by the authors, and a compilation of 17 350 values of Henry's Law constants for 4632 species, collected from 689 references is available at http://wwwhenrys-law.org
Abstract: Many atmospheric chemicals occur in the gas phase as well as in liquid cloud droplets and aerosol particles Therefore, it is necessary to understand the distribution between the phases According to Henry's law, the equilibrium ratio between the abundances in the gas phase and in the aqueous phase is constant for a dilute solution Henry's law constants of trace gases of potential importance in environmental chemistry have been collected and converted into a uniform format The compilation contains 17 350 values of Henry's law constants for 4632 species, collected from 689 references It is also available at http://wwwhenrys-laworg

1,935 citations

Journal ArticleDOI
TL;DR: The amorphous state is critical in determining the solid-state physical and chemical properties of many pharmaceutical dosage forms and some of the most common methods that can be used to measure them are described.

1,864 citations

Journal ArticleDOI
TL;DR: It is considered more feasible that the rate-deter-mining step is the cleavage of the C-H bond at the R-carbon atom, and the active site consists of an ensemble of metallic Auatoms and a cationic Au.
Abstract: ion from a primary OH group of glyc-erol. 223,231 A similar mechanism was proposed manyyears ago for alcohol oxidation on Pt/C, involving asecond step, the transfer of a hydride ion to the Ptsurface (Scheme 11). 8,87,237 We consider it more feasible that the rate-deter-mining step is the cleavage of the C-H bond at theR-carbon atom. A similar mechanism is now generallyaccepted for Au electrodes (Scheme 12). 238 Despite thestructural differences between Au nanoparticles andan extended Au electrode surface, there are alsosimilarities, such as the critical role of aqueousalkaline medium and the absence of deactivation dueto decomposition products (CO and C x H y frag-ments). 239,240 An important question is the nature of active siteson Au nanoparticles. Electrooxidation of ethanol onAu nanoparticles supported on glassy carbon re-quired the partial coverage of Au surface by oxides. 241 Another analogy might be the model proposed for COoxidation. 219,242,243 According to this suggestion, theactive site consists of an ensemble of metallic Auatoms and a cationic Au

1,784 citations

Journal ArticleDOI
TL;DR: The thermal stability and flame retardancy of polyurethanes is reviewed in this article, where a detailed description of TGA, TGA-MS and TGAFTIR methods for studying the decomposition mechanism and kinetics is also provided.

1,329 citations